Picture this the human speices could very well in the not too distant future have all reproduction done inside a very controlled enviroment(labratory) for optimum health of the speices with some special device for weeding out defects headed in a wrong direction and allowing the positive ones to be passed on by some kind of mathematical nonlinier formula that seems to speed up positive changes in the dna.
And as a result all sex relations never results in reproduction or transfference of decease because of this prosess.
Now if that were true would you like the casual view of sex, would you indugle is it if it was morally exceptable and no one really worried about who belongs to who, and it was no big deal?